The present invention relates generally to the application of plastic coatings to the bodies of the cell poles of an electric battery, particulary cell poles which have been cast in unitary combination with a completely assembled plate group held in proper position for mounting within a holder.
Lead cell poles have long been used to make electrical connections in electric batteries. In order to promote a good, snug fit between the cell poles and the container cover through which they pass, such cell poles are advantageously provided with a plastic coating and passed through a tube of appropriate diameter provided in the cover in such a way that the required tightness for a proper fit is assured as a result of the frictional contact developed between the pole coating and the plastic material of the tube. Such pole sealing is known, for example, from DE-OS No. 27 57 568, and represents an improvement over conventional pole sealing techniques wherein lead bushes are recessed or injection-molded in the cover and later welded to the pole body, a process which is usually cumbersome, and which must take place after assembly of the battery.
The impetus to steadily reduce the time required to manufacture a battery, as a consequence of an increasing level of automation, has led to the development of means for casting the connecting straps and cell poles, including the pole inserts (made, for example, from brass), directly onto plate groups which have previously been completely assembled and placed within a holder in proper position for subsequent mounting in the cell container, all in a single operation according to a modified cast-on-strap (COS) process. However, this process eliminates the possibility of subsequent individual processing of the cell poles because the poles, which are spaced closely to one another, represent a mutual obstacle to one another. This makes the plastic injection coating of such cells poles especially difficult.
Thus, the present invention has as its primary object to provide a process which permits the plastic injection coating of the bodies of cell poles in a reliable and efficient manner, and an apparatus for carrying out such a process.